Peptide hydrogels assembled from nonionic alkyl-polypeptide amphiphiles prepared by ring-opening polymerization

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Amphiphiles are molecules with both hydrophilic and hydrophobic parts.
• Hydrogels are water-swollen polymer networks with diverse applications.
• Controlling hydrogel properties is crucial for advanced material design.

Purpose of the Study:

• To synthesize novel alkyl-polypeptide (AP) amphiphiles.
• To investigate the self-assembly behavior of these AP amphiphiles in water.
• To characterize the properties of the resulting hydrogels.

Main Methods:

• Ring-opening polymerization of alpha-amino acid N-carboxyanhydride to create polypeptide segments.
• Functionalization of poly-L-glutamate with diethylene-glycol-monomethyl-ether.
• Preparation and characterization of hydrogels using CryoTEM and AFM.

Main Results:

• Three AP amphiphiles were successfully synthesized.
• AP amphiphiles spontaneously self-assembled into transparent hydrogels in water.
• The hydrogels exhibited shear thinning behavior and tunable strength modulated by alkyl tails.
• CryoTEM and AFM revealed hydrogel formation via nanoribbons from intermolecular interactions.

Conclusions:

• Novel AP amphiphiles can form self-assembling hydrogels.
• Hydrogel properties like strength are controllable via hydrophobic interactions.
• The nonionic poly-L-EG(2)Glu segments play a key role in hydrogel formation through intermolecular interactions.